C&G 2391 Exam Questions - With Answers

1. For a continuity test on a ring final circuit state:
a) The other test that is automatically performed
b) The effect on the resistance reading between P and N taken at a spurred socket outlet compared with that taken at a socket yet on a ring
c) The significance of the reading taken between and CPC at each socket outlet on the ring

2. A continuity test between P and N is conducted on a final ring circuit comprising 2.5mm2/ l.5mm' thermoplastic (pvc/pvc) cables. Readings at the socket outlets close to each other indicate an increase value to that of all the other sockets, state:
a) The instrument used for the test
b) Two possible reasons for the increased readings

3. For a ring final circuit test, state:
a) Why the test between P and N is conducted
b) The reason why phase to neutral readings at each socket would increase towards the mid-point of the ring then decreases again.
c) The other test that is automatically conducted.

4. The tests results table below were obtained from a ring final circuit continuity resistance test. State whether the readings for EACH socket are satisfactory or unsatisfactory. Give possible reasons for those readings that are unsatisfactory. Note: Phase, Neutral and C.P.C loops : 0.8 Ohm

5. A ring final circuit continuity test revealed incorrect polarity on three sockets outlets, The results were:

6. A continuity test is conducted on a ring final comprising 2.5mm2/l.5mm2 thermoplastic (p.v.c/p.v.c) cable.
The first resistance values are shown below, state:
a) Why the P to CPC value is greater than P to N value
b) The value to be expected at each socket between P and N after completing the test cross-connections
c) The value to be expected at each socket between P and CPC after completing the test cross connections. (p.v.c/p.v.c) cable.

7.A test is to be conducted on a cooker circuit to establish the value of (R1 +R2) state:
a) The instrument to be used
b) The meaning of (R1 +R2)

8. When inspecting and testing the main equipotential bonding conductors during an initial verification, state:
a) Where they should be connected on Gas and Water services
b) The instrument to be used for checking continuity
c) The action to be taken regarding the test leads

9. The CPC continuity of a radial circuit comprising four sockets outlets is to be tested. If the test method uses a temporary link between phase and earth in the distribution board, state:
a) At which points in the circuit die test should be conducted
b) The conductors between which the test should be made
c) The significance of the reading at the furthest point.

10. State the following:
a) A Statutory document that requires a person to be ‘competent’ in order to work on an electrical system
b) The title given to such a person whilst testing a system
c) The legal status of BS 7671

11. With regards to the H and SE GS38 recommendations, state:
a) Two requirements regarding instrument test leads
b) The legal status of GS 38

12. State the:
a) British standard number relating to the wiring of electrical installations
b) Statutory document relating to inspection and testing
c) Non-statutory document that gives details of the procedures for inspection and testing

13. A new shower unit has been installed in an existing installation.
a) State the three documents that must be completed.
State:
a) A Statutory document that is relevant to electrical systems
b) A Non-statutory document that details the use of electrical test equipment
c) A Non-statutory document that sets out the requirements for electrical installations

14. An inspection and test is to be conducted on a new installation, state:
a) The type of verification to be carried out
b) The documentation that will need to be completed

15. State the legal status of each of the following:
a) British Standard 7671
b) The IEE Guidance Note 3 Inspection and Testing
c) The Electricity at Work Regulations 1989